Out-of-the-box, Easy Digital Downloads sends people to checkout even when a product is free.
I wanted to avoid this step by just collecting a customer’s email address and sending them a confirmation email without them having to leave the sales page. So, I created EDD Free Purchases.
It setups a shortcode you can use to embed an email signup form on any page on your site. When the customer submits their email, the product is automatically purchased and they’re sent a confirmation email.